DSM2 v8.1.2 contains a number of major changes. Some of the highlights are:

Qual formulation corrections for dispersion

NAVD88 Datum

Improved hydro geometry calculation

Hydro runs 2x faster than 8.0.x versions

Qual tidefile outputs average concentration for every channel

PTM filtering feature

Qual mass balance synced with Hydro on every time step

Data improvements for boundary, gate operations and rules

These changes required a recalibration of the model and those results are available in this package as well as documented in the annual reports. Please click here to download DSM2 V8.1.2.

DSM2 Version 8.0.6 Release(11/17/2010)

DSM2 v8.0.6 contains some changes to reaction kinetics that we have been testing for some time.

Corrects a solar radiation rate that was mischaracterized in the ammonia equations. The issue dates back to a typo in the original QUAL2E documentation, which was the basis for non-conservative reactions in DSM2.

The integration technique for source terms has been replaced by an adaptive Runge-Kutta scheme that is more robust near zero concentration. Previously, constituent concentrations could cross below zero and then react erratically. This was particularly likely to happen when the initial or boundary concentration was not carefully chosen to be physical.

The model was not mixing parcels adequately in dead end sloughs and other regions where the upstream side of a channel had zero flow (including the Delta Cross Channel when the gate is closed). The lack of mixing became more apparent with non-conservative constituents because parcels are left to react in isolation.

Overview
The Delta Simulation Model II (DSM2) is a one-dimensional
mathematical model for dynamic simulation of one-dimensional hydrodynamics,
water quality and particle tracking in a network of riverine or estuarine
channels. DSM2 can calculate stages, flows, velocities, mass transport processes
for conservative and non-conservative constituents including salts, water
temperature, dissolved oxygen, and trihalomethane formation potential, and
transport of individual particles. DSM2 thus provides a powerful simulation
package for analysis of complex hydrodynamic, water quality, and ecological
conditions in riverine and estuarine systems.

DSM2 currently consists of three modules, all of which come with the
current distribution: HYDRO, QUAL, and PTM. HYDRO simulates one-dimensional
hydrodynamics including flows, velocities, depth, and water surface elevations.
HYDRO provides the flow input for QUAL and PTM. QUAL simulates one-dimensional
fate and transport of conservative and non-conservative water quality
constituents given a flow field simulated by HYDRO. PTM simulates pseudo
3-D transport of neutrally buoyant particles based on the flow field simulated
by HYDRO. PTM has multiple applications ranging from visualization of
flow patterns to simulation of discrete organisms such as fish eggs and
larvae.

DSM2 Version 8 is currently in Version 8.1.2. Please send comments and questions
to Min Yu at minyu@water.ca.gov.

Getting Started
Welcome to DSM2. This section of the documentation is intended to help you
acquire and install dsm2, test that it is working and understand the layout of
the distribution. After you have taken these steps, you will probably want to
tackle the tutorials in the /tutorials folder of the distribution or consult
the documentation or grid map in the /documentation folder -- a link has been
provided on the start menu to make the documentation easier to find.

Download and Installation
DSM2 is distributed by the California Department of Water Resources Delta
Modeling Section. Currently we distribute Windows executables, tutorials
and a data package with templates for common studies plus a map of the
standard Delta grid. We expect to release a source code distribution in
late Fall, 2009.

The current version of DSM2 is DSM2 Version 8.1.2 (370 Mb).

DSM2 comes with a binary installer, and you should be able
to set it up easily with the default installation. There are two limitations:

DSM2 is tested only on Windows XP. It has a history of working on NT,
and we would love to hear from you if you can confirm it works on
Windows Vista.

You need administrative permission to install the package.

You should not set it up in a location with spaces. We recommend:
D:\delta\dsm2 or C:\delta\dsm2...

Set it up on a drive with a lot (gigabytes) of room. This will make it easier to
use in-place

Recommended Third Party Extras
DSM2 comes with a numerical model and scripting capabilities.
It is easier to use the model if you also have a text editor with
syntax highlighting, a tool for differencing
text files ("diff tool"), a dss viewer and an hdf5 viewer.

Open Command Window Here is a free "power tool" distributed by Microsoft (the download
links are on the right hand side next to the description of the tool).
It allows you to get a command window by right clicking a location in Windows
file explorer. The tool is essential for working with DSM2 efficiently.

Notepad++
is a text editor that works well with DSM2 input data and integrates
nicely into the Windows file explorer. We support the editor with syntax
highlighting. See the /extras folder.

DiffMerge is a good
free differencing tool for text files.
Beyond Compare
is an inexpensive commercial product that is intuitive and also compares Word files.

Vista, one of the first graphical tools for examining data in HEC-DSS format,
comes with DSM2 in the /dsm2/vista/bin directory.

HEC-DSSVUE is distributed by HEC and is actively maintained. Most people use DSSVUE
as their primary tool with Vista for specific tasks. An Excel add-in for DSS data
is also available on the HEC web page.

HDFView and
HDF-Explorer are two independent
browsers for the HDF5 file format. This lets you look inside a tidefile, one of the
outputs of the model. You only need one of them.

Test Launching DSM2
The first step is to see whether the installation was successful. To do
this, get a DOS-style command prompt window and type from any location:
C:\>hydro -v
DSM2-Hydro 8.1.2
Usage: Hydro input-file

If you got a message like the one above, you are up and running! Your next
stop should be Tutorial #1 or Delta Tutorial #1.
Look in the /tutorials folder of the distribution. The Basic
Tutorials (Tutorial 1-6) feature most of the nuances of the model using
a very simple grid and are an excellent way to learn about the model
-- including subtleties that are new or caused confusion in the past.
The Delta Tutorial series are more applied -- tasks on the Delta.

If instead you get this: C:\>hydro -v
'hydro' is not recognized as an internal or external command, operable program
or batch file.